I propose a mixture.
When talking about the GAME (i.e. the rules), precise language is a must.
So the chapter called 'Combat' that describes the mechanics should be clear, concise and use specific terminology to ensure that the mechanics are well explained.
However, when describing magical items, spells, the fluff for classes, the gods, domains, equipment, please use some descriptive, evocative text.
Yes, you can have the crunch at the end, but as I keep repeating, not EVERYTHING in an RPG can be summed up in a quantitative manner nor should you try.
(This, btw, is why I do not like 4e: if it could not be summed up with numbers, it got thrown out of the game. 4E is lessened by this approach)
A good example of a fun to read book is Fr4 The Magister. The entire book is a description of magical items.
Now, you can't have that level of description for all the things I listed above but, at least, give me some flavour text for items and spells.
Web isn't just 'causes X by Y squares to become difficult terrain' or whatever. It's 'Magical strands of a sticky web-like substance fills an area of X by Y. These strands stick to all the objects in the area or passing through causing the area to become difficult terrain'
Presently, 4e goes the former way and is about as exiting as reading the specs in a manual. (The most boring part of a boring text).